Simulation of dielectric properties and stability of clusters (H2O)i, CO2(H2O)i, and CH4(H2O)i

Molecular dynamics method is used for studying complex permittivity ɛ and the stability of individual water clusters as a function of the number of involved molecules (7 ≤ i ≤ 20) and also the corresponding characteristics of water aggregates with a captured CO2 or CH4 molecule. Absorption of the latter molecules leads to considerable changes in dielectric properties and stability of clusters. In particular, upon the addition of a CO2 molecule to a water cluster, the oscillation parameters of the real and imaginary parts of the permittivity change. Capture of a CH4 molecule by a water aggregate changes the ɛ(ω) dependence from the relaxation to resonance type. For i ≥ 15, the thermal stability of individual water clusters can be lower than that of aggregates CO2(H2O)i and CH4(H2O)i. The mechanical stability of (H2O)i ≥ 13 clusters can exceed that of heteroclusters under consideration. Clusters (H2O)i and CO2(H2O)i have approximately the same dielectric stability, whereas aggregates CH4(H2O)i exhibit lower stability with respect to electric perturbations.